System and method for separating materials using stirring motion, stratification, and vertical motion

ABSTRACT

A cyclonic separation and materials processing method and system is presented in which materials entry at one end and which is arranged so that the materials that enter will be given a tangential velocity component as they enter. Specific embodiments include a three-dimensional sorting system with the use of an outward centrifugal motion and up/down (or vertical) motion flow of water or other media, which can be thought of as “a three-dimensional separation”.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/060,395, now U.S. Pat. No. 10,486,164, which is a national phaseapplication of International Application No. PCT/US2016/065458, filedMay 22, 2015, which application claims the benefit of and priority toU.S. Provisional Application Nos. 62/264,141 filed on Dec. 7, 2015 and62/286,346 filed Jan. 23, 2016, the entire contents of which are allincorporated herein by reference.

TECHNICAL FIELD

This application relates to a method and system for sorting materials.More specifically, this application relates to a method and system thatemploys an impeller or stirrer inside a cyclone to sort and recovermaterials from waste stream.

BACKGROUND

Recycling of waste materials is highly desirable from many viewpoints,not the least of which are financial and ecological. Properly sortedrecyclable materials often can be sold for significant revenue. Many ofthe more valuable recyclable materials do not biodegrade within a shortperiod. Therefore, recycling such materials significantly reduces thestrain on local landfills and ultimately the environment.

Separation and recovery of solid waste and waste-stream components canbe accomplished using many techniques, processes and devices. Costs andcomplexity of separation, particularly the inability to provideclean/perfect separation of recoverable fractions, are the usualdrawbacks, delivering a disadvantage to many recycling processes wherethe process costs more than the resulting recovered/recoverablematerials are capable of generating in the market. The quantity of wasteto be treated has a direct effect on the ability to use known processesfor separation and recovery of components, and/or the cost-effectivenessof those processes. This combination of diverse materials and diversematerial sizes, densities, shapes and moisture content provide a uniquechallenge in separating and recycling specific materials in an efficientmanner. The ability to efficiently separate and concentrate recyclablematerials at high throughputs from the different waste streams reducesthe negative environmental impact of these materials, as less of thisresidue will be disposed of in landfills.

Accordingly, there is always a need for improved separation techniquesand systems. It is to this need, among others, that this disclosure isdirected.

SUMMARY

A cyclonic separation and materials processing method and system isdisclosed in which materials enter at one end and which is arranged sothat the materials that enter will be given a tangential velocitycomponent as they enter. Certain embodiments include a three-dimensionalsorting system with the use of an outward centrifugal/stirring motion,an up/down (or vertical) motion from the flow of water or other media,and a media separation, which can be thought of together as provide “athree-dimensional separation.” A low-frequency, high-amplitude pulsingof the media can cause a good distribution of the particles in thecyclone.

One embodiment includes a separator for the separation of a wastestream, the separator having a cyclone, a stirrer (e.g., an impeller),and an inlet for accepting the waste stream; a dewatering device; and ascrew conveyor. The dewatering device can be a dewatering screen,dewatering conveyor, a screw conveyor or bucket elevator. The cyclonehas a cylindrical housing having an interior surface, and inlet and anoutlet.

In another embodiment, the separator can have a fixed screen thatscreens larger sized materials from reaching the bottom of the cone,which is provided at an angle inside the conical housing of the cyclone.Water or other media can fill the entire cyclone to a predeterminedlevel. On the top of the cyclone, an impeller or stirrer may be used toagitate the water or to create a centrifugal motion. When the water hitsthe rotating impeller, energy of the impeller is transferred to thewater, forcing the water outward (centrifugal force, jolt surge effect).The water is displaced outward, and more water can enter the suctionside of the pump to replace the displaced water. Materials to be sortedcan enter the cyclone through a feed chute/inlet located, e.g., on thetop of the cyclone next or above of the impeller. In one example, theimpeller comprises a shaft that extends from the center-top cylindricalportion of the cyclone down towards the cone. On the bottom of theshaft, fixed paddles are provided. In operation, the impeller rotates togenerate a centrifugal motion of the water. The centrifugal motion orstirring motion may be generated by the impeller or stirrer.

Another embodiment includes a method for separating and recoveringmaterials from a waste stream, the method comprising (a) feeding thematerials into a separator having media that has specific gravitybetween about 1.0 and 3, wherein the separator has acentrifugal/stirring motion and a vertical motion therein, (b) flowingmedia into the cyclone to generate the specific gravity, (c) collectinglight materials that float on a top portion of the separator, and (d)collecting the heavy materials through a bottom portion of theseparator.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Unless otherwise defined, alltechnical and scientific terms used herein have the meaning commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. All publications, patent applications, patents, and otherreferences mentioned herein are incorporated by reference in theirentirety. In case of conflict, the present specification, includingdefinitions, will control. Other features and advantages of theinvention will become apparent from the description, the drawings, andthe claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a perspective view of the three-dimensional separatoraccording to this disclosure.

FIG. 1B is another perspective view of the three-dimensional separatoraccording to this disclosure.

FIG. 2 is a cross-sectional top view of the three-dimensional separationapparatus according to this disclosure.

FIG. 3 is a perspective view of another three-dimensional separatoraccording to this disclosure.

FIG. 4 illustrates a method of separating materials according to thisdisclosure.

DETAILED DESCRIPTION

In general, this disclosure includes methods and systems for separatingmaterials in a waste stream. The methods and systems can separate aheterogeneous mixture of particulate solids. The solids can have aplurality of different specific gravities, which can be sorted using athree-dimensional sorting system that may include, e.g., a cylinder witha cone beneath, together referred to as a cyclone.

Certain embodiments include a three-dimensional sorting system with theuse of an outward centrifugal/stirring motion, an up/down (or vertical)motion from the flow of water or other media, and a media separation,which can be thought of as provide “a three-dimensional separation.” Alow-frequency, high-amplitude pulsing of the media can cause a gooddistribution of the particles in the cyclone. A low-frequency,high-amplitude pulsing of the media can cause a good distribution of theparticles in the cyclone. In one example, the speed of the stirrer canbe reduced to slow the stirring of the media, which can increase theresidence time of the material and media so that particles/material havemore time to separate. In certain examples, the speed of the stirrer canbe between about 1 to 600 ft per second.

One embodiment includes a separator for the separation of a wastestream. The separator has a cyclone having a screen, a stirrer (e.g., animpeller), and an inlet for accepting the waste stream; a dewateringdevice; and a screw conveyor. The dewatering device can be a dewateringscreen, dewatering conveyor, a screw conveyor or bucket elevator. Thecyclone has a cylindrical housing having an interior surface, and inletand an outlet. A fixed screen, around the base of the cyclone, screenslarger sized and impedes materials from reaching the bottom of the cone.The cone has an angle inside the conical housing of the cyclone. Wateror other media can fill the entire cyclone to a predetermined level. Onthe top of the cyclone, an impeller may be used to agitate the water ina centrifugal motion. When the water hits the rotating impeller, energyof the impeller is transferred to the water, forcing the water out(centrifugal force, jolt surge effect). The water is displaced outward,and more water can now enter the suction side of the pump to replace thedisplaced water. Materials to be sorted can enter the cyclone through afeed chute/inlet located, e.g., on the top of the cyclone next or aboveof the impeller. In one example, the impeller comprises a shaft thatextends from the center-top cylindrical portion of the cyclone downtowards the cone. On the bottom of the shaft, fixed paddles areprovided. In operation, the impeller rotates to generate a centrifugalmotion in the water. The centrifugal motion is generated by theimpeller.

FIGS. 1A, and 1B show an exemplary apparatus employing athree-dimensional separation process and system. The separator 10 has acyclone 20, an impeller 30, and an inlet 40 for accepting the wastestream, a dewatering device 50; and a screw conveyor 60. As can be seen,material or the waste stream can be fed through a feed chute 40 into thethree-dimensional separator 10 on the top section of the cyclone 20. Thecyclone 20 generally has a cylindrical top section 14 and a conicalbottom section 12—however, the cyclone 20 need not have a conical bottomportion. The impeller 30 agitates in centrifugal motion or stirs themedia, which flows into the cyclone. A constant flow of media, or apulsating flow of water or media, is provided through a media circuitwith, e.g., an inlet pipe or chamber 25 connected to the bottom portionof the cone 12, which creates a vertical motion in the cyclone 20. Threeseparated products exit the three-dimensional separator 10 as follows: Afirst discharge for, e.g., the “lights” discharge through the passage45, a second discharge for, e.g., the fine discharge through “hutch”discharge 15, and a third discharge for e.g., the “heavies” dischargethrough the chute 47.

As can be seen, the lights discharge passage 45 can be provided with ade-watering screen 50 or similar de-watering device such as ade-watering conveyor, screw conveyor or bucket elevator. The heaviesdischarge 47 can be coupled with a discharge gate or a dewatering screwconveyor 60 as depicted on the figures. Finally, the hutch dischargedevice 47 can be provided with a pinch valve, rotary valve, de-wateringscrew conveyor, de-watering screen or a combination of such.

FIG. 2 shows an exemplary apparatus or system in which the cyclone 20has a fixed screen 40 located at an angle inside the conical section 12of the cyclone 20. A constant flow of water or media, or a pulsation ofthe media, is provided through e.g., an inlet pipe or chamber 25connected to the bottom of the cone 12 below the screen 40. Theseparator 10 has a cyclone 20, an impeller 30, and an inlet 40 foraccepting the waste stream, a dewatering device 50; and a screw conveyor60. As can be seen, material or the waste stream can be fed through afeed chute 40 into the three-dimensional separator 10 on the top sectionof the cyclone 20. In one embodiment, there is a screen in the cyclonethat is at an angle. The screen may be a size suitable for a specificrecovery application. The screen can be angle to allow the heaviestmaterials to sink to the bottom of the cyclone while allowing othermaterial to remain in the suspension. The angle of the screen can bebetween 40 degrees and 70 degrees from the horizontal axis of thecyclone. In one example, the screen is positioned at an angle of about55 degrees from the horizontal plane of the cyclone.

The term “screen” as used herein is intended to include any mesh-likesieve or grid-like device or perforated structure used to separateparticles or objects. The screen helps retain and prolong the exposureof the heavies to the processing fluid. In one example, the screen orscreens each have a mesh size of 2-4 mm. However, the mesh may be largeror smaller and also may vary from screen to screen. The screen can havea unique mesh orientation, depending on the application, to create amesh interference pattern along the axis between the top and bottom ofthe cyclone. For example, the mesh orientations of the screens areadjusted from one another about the central axis, although the degree orrotation between adjacent screens may be anywhere between 40 and 70degrees, depending upon the shape of the openings.

FIG. 3 shows another exemplary apparatus employing a three-dimensionalseparation process and system. The separator 10 has a cyclone 20, animpeller 30, and an inlet 40 for accepting the waste stream; adewatering device 50; and a screw conveyor 60. As can be seen, materialor the waste stream can be fed through a feed chute 40 into thethree-dimensional separator 10 on the top section of the cyclone 20. Thecyclone 20 generally has a cylindrical top section 14 and a conicalbottom section 12. Again, the bottom section need not be conical and maybe cylindrical. The impeller 30 agitates in centrifugal motion orlightly stirs the media, which flows into the cyclone from a mediacircuit. A constant flow of water or media, or a pulsating flow of wateror media, is provided through a media circuit with, e.g., an inlet pipeor chamber 25, which creates a vertical motion in the cyclone 20. Inthis embodiment, two separated products exit the three-dimensionalseparator 10 as follows: A first discharge for e.g. the “lights”discharge through the passage 45, and a second discharge for, e.g., the“heavies” discharge through the chute 15. As can been seen, the lightsdischarge passage 45 can be provided with a de-watering screen 50 orsimilar de-watering device such as a de-watering conveyor, screwconveyor or bucket elevator. A conveyor, e.g., a screw conveyor (notshown) can convey the heavies away from the separator. In certainexamples, using a larger sized media and/or a slower stirred can resultin increased separation.

The stratification from the vertical motion or up/down motion isgenerated through an axial connection provided underneath the screen inthe conical section of the cyclone. Such connection allows for water orother media to enter to the cyclone. Such water or media that entersthrough the axial connection generates an upward and downward motion,therefore the third-dimension of the separation apparatus. The axialconnection may also be tangential and in the form of a pipe or chamber.One example of the stratification apparatus can be an air-over-waterpulsating chamber or water pulsation generated in an air chamber. Insuch an example, air inside a chamber expands and contracts creating anupward and downward flow of water into the cyclone through the axial ortangential connection.

The centrifugal motion allows for materials to spin or stir inside thecyclone. The resulting centrifugal action causes heavier particles to bethrown towards the outer wall of the cyclone (or have a higher residencetime), and they are then allowed to slide down the cylindrical andconical walls towards the screen. The finer heavier recyclables thatsink to the bottom are small enough to pass through the screen openings,and are discharged at the bottom of the cone with the use of a dischargedevice such as a valve, movable gate or rotary valve that prevent thecontinuous discharge of water but allows the finer heavier recyclablesto exit when the device is energized. The lighter materials that stay insuspension on the top of the cyclone are eventually dischargedcontinuously by the carrying circular current through a tangentialpassage located on the high side of the cylinder. The materials can thenmove through the cyclone towards an outlet for the heavier fraction (orthe so called “underflow” fraction)

FIG. 3 illustrates a method or process for sorting materials, the methodcomprising feeding the materials into a separator having media that hasspecific gravity of about 1 to about 3, wherein the separator using acentrifugal motion and a vertical motion. In another example, the mediahas a specific gravity between 1.1 and 3. The media is pulsed or flowsinto the cyclone. The light materials can be collected from a topportion of the separator, the heavies can be collected through a middleportion of the separator, and the fines can be collected from the bottomportion of the separator. The lights may be fed into a sieve orprocessed otherwise. The heavies may be moved away using a conveyor,e.g., as a screw conveyor. The fines may be further processed,discarded, or combined with another material. The media can be water.The media can also have dirt, sand, glass fines, ferrous fines, ashresidue and combinations thereof. The media from each product may becollected and reprocessed in a media circuit, which is a known type ofcircuit. In an embodiment in which the separator does not have a screen,two products, namely, the heavies and lights would be collected. In suchembodiments, a media with a high specific gravity may produce betterresults (e.g., 1.4).

The rotational speed of the impeller as well as the frequency and strokeof the stratification apparatus of the cyclone may be varied to optimizethe separation process. Without intending to be bound to specifictheory, these two effects are combined into a single separation unit inwhich several principles come into play such as the ArchimedesPrinciple, which explains how the apparent weight of an object immersedin water decreases. Other principles applied due to thethree-dimensional separation includes the Hindered Settling effect, theConsolidation Trickling effect, as well as the Jerk Effect also referredto as Jolt Surge effect that is caused by both the centrifugal motioncreated by the impeller and the upward/downward movement of thestratification component.

The upward and/or downward motion of the media enhances the separationby reducing the amount of lighter materials that are misplaced orentangled with heavier materials that sink to the bottom of thethree-dimensional separator. Such upward and downward motion, referredto as the third separation dimension, can be provided through the axialor tangential pipe or chamber in the form of pulses that generateupwards and downward currents of other media, pulse chamber. Such inflowand outflow of water to the cyclone generates a rising current of waterthat improves the separation efficiency and a downward flow of waterallows for the heavier particles to stratify on top of the screenprovided inside the cone. The shear and suspension of the material alsohelps separate the material.

The heavier materials that sink to the top of screen are dischargedthrough a material discharge device such as a valve, gate, rotary valve,sealed bucket conveyor or sealed screw conveyor to allow for the heaviermaterials to exit the cyclone while reducing the amount of water ormedia that flows therethrough. The additional water or media that isrequired to make up for the lost water or media that abandons thecyclone through the lighter material discharge, fine heavier materialdischarge or the heavy material discharge zones may be added to thecyclone. The water supply should be the correct volume and pressure—toolow of flow and pressure may result in poor separation and too high offlow and pressure may cause instability in the cyclone.

The separated products produced in the three-dimensional separationapparatus or system may be designated as follows: (1) the “lights”,which are discharge through an exit passage located on the top of thecyclone; (2) the “fine heavies” or “hutch product”, which consists offine particles that have a specific gravity large enough that they sinkto the bottom of the cone/cyclone by passing through the openings of thescreen; and (3) the “heavies”, which consists of the heavies that sankto the bottom of the cyclone but are not small enough to pass throughthe screen. The system or separator can also discharge unwanted solidswith the heavies fraction.

In an alternate embodiment, the axial or tangential pipe or chamber maygenerate a constant inflow of water or media rather than constantpulsating streams of media. Such continuous up flow of water will stillgenerate the third-dimension of separation to enhance the efficiency ofthe separation and may be used when processing different materials. Forexample, the pulsating upward and downward motion may be used whenprocessing prone to entanglement recyclables such as recyclablescontaining insulated or bare wire. The inflow and outflow of water orother media will reduce the chances for light recyclables from ending onthe heavy fraction.

In another embodiment, the media or fluid used in the recovery systemmay be any liquid capable of washing the materials and causing the metalto suspend into the process fluid. In other embodiments, the recoverysystem may use chemicals which can extract and suspend the desiredconstitute. Examples of such solutions are well known to those of skillin the art. One example of such a solution is water. In otherembodiments, chemicals, minerals and or any magnetic material that canbe used to change the specific gravity of the fluid to obtain an actualconstant specific gravity range of 1.0 to 3.0 SG depending on theapplication. The 1.0 specific gravity separation chamber, because thereis no added suspension media component it, that is, the liquid is water.Another alternative for attaining specific gravities of greater than 1.0specific gravity media is through the use of magnetite or orferrosilicon, sand and mixtures thereof. In one example, the sand have asize less than 200 mesh, which is a byproduct of aggregate production,can be used. A specific gravity of about 1.6 can be used to separateorganic and inorganic materials, about 3 can be used to separate heavymetals, and about 1.8 to 2.0 can be used to separate aluminum/magnesium.

In another embodiment, in some cases the media includes inorganic dirt,sand, glass fines, ferrous fines, ash (e.g., incinerator bottom ash,automobile shredder residue (ASR)), or fines, and combinations thereof,which can be screened with a screen having 16 mesh or less to create asuspension or media having a specific gravity of 1.5 or 1.6 SG orhigher. In certain examples, the particles had a size less than 325 mesh(44 microns). In other examples, the particles had a size greater than200 mesh (74 microns). In such cases, the apparatus can use inorganicmedia fines that can come from automobile shredder residue fines,shredder fines from Hammermill operations, ferrous slag or inorganicfine byproducts from incineration and/or pyrolysis operations. Further,other minerals that may be mixed in a landfill containing metals can beused. In one example, fines from a ball mill process (of e.g., ash)having 200 mesh or greater can be used to generate media, which can beused for as media to obtain media up to 3 SG.

By using media with a specific gravity of 1.6 SG or higher, the costs toan operator can be reduced or nullified, that is, the costs to theoperator may be net zero. Media with a specific gravity of 1.6 SG orhigher can be separate organics and inorganics. A main differencebetween organics and inorganics is the fact organics contain carbon andthat organics can then be used to produce a BTU feedstock forincineration, pyrolysis, or other separation to produce salableplastics, rubber, foam etc.

The material fed into the separator may be size reduced and classifiedthrough techniques for converting streams into fragments andparticulates. For example, a shear shredder or screening may also beused to shred or size reduce the solid wastes and waste streams, tocause size reduction, fragmentation and particulate formation. In oneexample, the material is sized from about 0-12 mm, which in the case ASRand electronic scrap, the majority of recovered material will includeinorganics, glass, rock, any other minerals. The material can also besized from about 12 to about 100 mm, and greater than 100 mm. The solidwastes and waste stream materials can be size fragmentized into, e.g.,discrete sizes. In some examples, the feed size is not the same as thescreen size, which can lead to improved performance.

The simultaneous centrifugal and vertical motions of thethree-dimensional separator enhances the separation efficiency of thematerials by processing high throughputs and reducing the limitations oftypical recyclable materials such as moisture content. Thethree-dimensional separator may provide a cost-effective method ofconcentrating recyclable materials into discrete specific gravitiesdoing so at higher throughputs than typical sorting technologies. Suchdiscrete specific densities are determined by the centrifugal speed ofthe water or media generated by the impeller as well as by the inflowand outflow of water through the bottom pipe or pulse chamber. Morenarrowly sized fragments can provide for the better separation.

In another embodiment, there can be multiple separation systems that usetwo or more separators to separate materials in a mixture. Themultistage systems can include multiple cyclone separators.

Although the present disclosure has been described in detail, it shouldbe understood that various changes, substitutions, and alterations canbe made herein without departing from the spirit and scope of thedisclosure as defined by the appended claims. The application describesparticular embodiments. Other embodiments are within the scope of thefollowing claims.

The invention claimed is:
 1. A separator for separating and recoveringmaterials from a waste stream, the separator comprising: a source of thewaste stream; a cyclone having an impeller, a feed chute, and an inletfor accepting media, wherein the cyclone has a top section and a conicalbottom section, the inlet is within the conical bottom section, and thewaste stream enters the cyclone through the feed chute, the impellerrotates in a first direction about an axis in the cyclone; a source ofmedia having a specific gravity between 1.1 and 3.0, wherein the mediaenters the conical bottom section through the inlet as a flow of mediaor a pulsating flow of the media, and the source of media is in fluidconnection to the cyclone through the inlet generating an upward flowwithin the cyclone; a first discharge passage for a collecting a lightfraction; a second discharge passage for collecting a heavy fraction; athird discharge passage, below the second discharge passage, forcollecting a fine fraction.
 2. The separator of claim 1, wherein theseparator is operatively connected to a dewatering device.
 3. Theseparator of claim 1, wherein the dewatering device is a dewateringscreen.
 4. The separator of claim 1, wherein the dewatering device is adewatering conveyor, a screw conveyor or bucket elevator.
 5. Theseparator of claim 1, wherein the media has dirt, sand, glass fines,ferrous fines and combinations thereof.
 6. The separator of claim 1,wherein the media is pulsed with an air-over-water chamber.